Select a solution of known concentration appropriate for the analysis of the analyte in question. In general, the titrant is a substance known to react with the analyte completely, yielding a change noticeable with a chemical indicator. For example, if the pH of a solution known to be acidic was to be analyzed a good titrant would be 0.1 Molar NaOH.
Prepare for analysis by loading a burette with the titrant, placing a measured portion of analyte in an Erlenmeyer flask, and dropping two or three drops of indicator in with the analyte. The type of indicator necessary varies widely between experiments; for measuring pH, toluylene red (which changes color as pH changes from acidic to basic or vice versa) would be a good choice.
Take note of the starting volume of solution in the burette and slowly add titrant to the Erlenmeyer flask, stirring continually, until the indicator begins to change color. Often the solution will change color slightly, and then go back. Add more titrant drop by drop until the solution changes color and remains. Take the difference between the starting and ending volume of solution in the burette to get the total volume used.
Calculate the total moles of titrant used by multiplying the total volume used in liters (L) by the concentration in Molarity (moles per liter). Note: burettes are marked by the milliliter (mL) and 1 L = 1000 mL, so the total volume measured must be converted from mL to L. For example, if 34.3 mL of 0.1 Molar NaOH were used then the total number of moles NaOH used would be [34.3/1000] x 0.1 = 0.00343 moles.
The number of moles of titrant used is equivalent to the number of moles of analyte originally present. Using this information and the initial volume of analyte used, the concentration of the analyte may be calculated. In line with the previous examples, if 0.00343 moles of NaOH titrant were used then 0.00343 moles of H+ were originally present in the analyte. Supposing that we had measured out 10 mL of analyte for analysis, the initial concentration of H+ would have been 0.00343 moles divided by 0.01 liters which is 0.343 Molar. Further, the pH would be --log(H+ Molar) which is 0.46, a very highly acidic solution indeed.